In addition to the others' comments, it brings to mind the carpet-sustain pedal leverage interface. Sometimes customers are very accustomed to the feel of the pedal's leverage, and then believes something is "broken" when it's really that the piano had been moved onto a very plush carpet, or a throw rug or mat has been placed just under the pedal. The opposite perception can be caused by moving the piano from the plush carpet to a wood floor. Patrick Draine
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